In electric vehicles powered by an electric motor, and hybrid vehicles that are powered using a combination of an electric motor and an internal combustion engine, etc., an electric power converting apparatus is mounted that converts electric power from a battery into electric driving power that is supplied to the electric motor, for example. The electric power converting apparatus includes: electrical components such as a power module that includes switching elements such as insulated gate bipolar transistors (IGBTs), a cooler that radiates generated heat from the power modules, a controlling circuit board that controls driving of the power module, etc.; and a housing that houses the electrical components, and that protects the electrical components from external dust, etc. In electric vehicles and hybrid vehicles, there is demand for good collision safety and comfort, and in mounted electric power converting apparatuses, shapes that enable effective use of space are desired. For effective use of space, it is desirable for the electric power converting apparatus to be compact, and for vibration resistance to be high so as not to be damaged even if mounted to positions on which vibrational loads from the engine and road surfaces act easily, such as above a transaxle inside an engine compartment, etc. Among the parts that are mounted to the electric power converting apparatus, since the controlling circuit board in particular is thin and has a large area compared to other parts, it resonates due to vibration acting from the transaxle, and its displacement amplitude is great, resulting in mounted parts being damaged.
In consideration of such conditions, various techniques have been proposed that attempt to make the controlling circuit board highly vibration-proof.
In a conventional electric power converting apparatus that is described in Patent Literature 1, for example, an attempt has been made to make a controlling circuit board highly vibration-proof by fixing to and holding, by a highly rigid circuit board holding bracket, a single controlling circuit board among a plurality of controlling circuit boards that are disposed so as to be stacked on a power module.
In a conventional automotive air-conditioner controlling apparatus that is described in Patent Literature 2, an attempt has been made to make a controlling circuit board highly vibration-proof by supporting a plurality of controlling circuit boards using supporting posts that pass through.